Flow Analysis in Polymer Processing of Fiber Reinforced liquid Crystalline Polymers

在这项工作中，我们分析了速度场和分子取向的纤维增强液晶聚合物（LCP）的聚合物加工过程中，既有纤维取向的增强和分子的一个。采用TIF模型和Doi模型对含圆柱和圆柱阵列的平行平板中的LCP流动进行了数值模拟。并利用羟丙基纤维素（HPC）溶液进行了实验研究。本工作取得的主要成果如下1.本文用TIF模型和Doi模型计算了含圆柱体的平行平板间流动中的分子排列分布。结果表明，在纤维间LCP的流动中，应特别注意结晶器后焊缝的出现.在TIF模型的模拟中，可以清楚地看到，在圆柱阵列几何结构中，分子排列很大程度上受到发散和会聚流动的影响.在圆板间纤维悬浮液径向流动的实验中，发现液晶相纤维取向的序参量小于各向同性相纤维取向的序参量。结果表明，HPC溶液中液晶相速度场的微观不均匀性是导致这一现象的原因之一。

In this work we analyzed the velocity fields and the molecular orientations in the polymer processing of fiber reinforced liquid crystalline polymers (LCPs) which had both reinforcements by fiber orientation and molecular one. The TIF model and the Doi model are applied to the numerical simulations of the flows of LCPs in the model geometries ; parallel plates containing a cylinder and cylinder arrays. The experimental investigations are also performed by using the solutions of hydroxypropylcellulose (HPC). Results obtained in this work are as follows1. The distribution of molecular alignment in the flow between parallel plates containing a crylinder is obtained by using the TIF model and the Doi model. From the result it is showed that a special attention should be paied to the occurrence of weld behind the crylinder in the flow of LCPs beteen fibers.2. In the simulation by the TIF model it becomes clear the molecular alignment is largely affected by diverging and converging flows in the cylinder array geometries.3. In the experiment of the radial flow of fiber susupensions in LCPs between circular parallel paltes, it is found that order parameter of fiber orientation in liquid crystal phases is less than that in isotropic phase. It is suggested that micro inhomogeneity in a velocity field in the liquid crystal phase of HPC solutions is one of this reason.